1. Field of the Invention
This invention relates generally to a cassette tape recording and/or reproducing apparatus, and more particularly to a cassette tape recording and/or reproducing apparatus, such as a cassette tape video recorder or the like, which is capable of selectively loading either of a large-sized tape cassette and a small-sized tape cassette.
2. Description of the Prior Art
In cassette tape recording and/or reproducing apparatus, such as a cassette tape video recorder (hereinafter referred to as a "VTR"), a pair of right and left position reference pins and a pair of right and left height reference pins are provided on a chassis in the apparatus, and the bottom plate of a tape cassette loaded in the apparatus is engaged with these pins so as to put the tape cassette in its horizontally and vertically exact position by the former pins and in its vertically exact position by the latter pins. And generally, the front side part of the bottom plate near the side of an opening for tape-loading is engaged with the position reference pins, and the right and left corners on the rear side of the bottom wall that are the opposite side for the opening are engaged with the respective height reference pins.
In the meantime, the recent VTR is often so constructed as to be able to record on or reproduce from tape cassetes of more than two sizes that are selectively loaded therein, in which the spaces between a pair of right and left reels are different from one another, such as between the large-sized cassette and the small-sized cassette.
In the VTR of this sort, a pair of right and left reel bases are automatically moved so as to make the space between the reel bases coincide with the space between the reels of the loaded cassette, such as the large-sized cassette or the small-sized cassette, and generally, the reel bases are moved together with the reel motors which drive the reel bases.
However, if the height reference pins of the VTR engaging with the corner portions on the rear side of the small-sized cassette are carelessly projected from the chassis, the height reference pins get in the way of the paths of the reel basses and reel motors.
In order to overcome the above problem, provided in the VTR of this sort is only one height reference pin engaged with the small-sized cassette at the center of the rear side of its bottom plate but the height reference pin provided like that makes it difficult to provide a guide for making the center line with respect to the width of the small-sized cassette coincide with that of the cassette holder, the guide being requisite while the small-sized cassette is inserted in a cassette holder of the VTR.
Furthermore, the height reference pin is generally engaged with the corner portion of the bottom plate of the cassette because the corner portion is rigid enough to obtain the exact positioning of the cassette. On the contrary, the center portion on the side of the bottom plate is not rigid enough and apt to be deformed when the height reference pin is engaged therewith, so it is difficult to obtain the exact positioning of the cassette.